Preselecting mechanism



1366- 15, 1942' .1. H. WILLIAMS PRESELECTING MECHANISM Filed Aug. 8,1940 2 Shee'tgs-Sheet l Dec. 15, 1942. J. H. WILLIAMS 2,305,123

PRESELECTING MECHANISM Filed Aug. 8, 1940 2 Sheets-Sheet 2 6 R M mwPatented 15, 1942 s PATENT OFFICE ransnnnc'rmo MECHANISM John H.

Williams, Chicago, Ill., assignor to Oak Mtg. 00., a corporation ofIllinois Application August 8, 1940', Serial No. 351,883

16 Claims.

This invention relates to preselecting mechanism and is particularlyuseful for indexing one of a number of predetermined index positions ofany device normally movable over a continuous range between two endpositions.- In one form, the preselecting mechanism is applied to a gangcondenser, which may be the. tuning ,element of a radio receiver. Suchcondensers are ordinarily movable over a, definite angular range,usually about 180.

However, the mechanism may be applied to any means movable over a curvedor straight path. element consists of a core of compacted iron particlesmovable in and out of a pair of windings in transformer. relationship.The movement of the core alters the inductance of the transformer andthus affects the receiver tuning. The invention is shown applied to thiskind of tuning means also.

Various preselectors have been made for the above purposes. Most havebeen of the pure Thus in some radio receivers, the tuning other endposition by the power drive and after I manual type in which a button orlever is operated and the power spent in the operation furnished themotive power for indexing purposes. This is unsatisfactory in someinstances. Thus an operator may actuate the mechanism by an impulse tooquick and short to permit the mechanism to reach its new indexedposition. In addition, the movable member may require substantial efforton the part of an operator, which effort it is desired to eliminate.

While attempts have been made to provide a power. drive forpreselectors, they have'been unsuccessful. The lack of success has beendue carried by the rotor shaft it. As is clearly evi-' to the extremecomplexity, making forhigh cost and doubtful freedom from trouble, andalso to the complexity of manipulation on the part of an operator. Y

By virtue of the invention herein, a simple, reliable device is providedand the manual operation is like an ordinary push button preselector. Infact, in the absence of power, the device hecomes an ordinary mechanicalpreselector.

In general, the invention contemplates a constant bias on the indexedmeans, to one of its two end positions. When the preselector button isoperated to select an index position, the previous button settingdisappears. The button being operated'upon. is retained in fixedposition and determines a stopping point for the indexed meansintermediate its end positions. The power drive operates to pull theindexed means against its bias toward the other end position. After theindexed means has been driven to its the stopping point has beenselected, the power drive is de-energized and the normal bias returnsthe indexed means to'the preselected stopping point.

Referring to the drawings:

Figure 1 shows a plan view of a two unit preselector applied to acondenser;

Fig. 2 is a section on 2-2 of Fig. 1 of the preselector;

Fig. 3 is a section on 3-3 of Fig. 1 showing the condenser and actuatingsolenoid;

Fig. 4 is an exploded view of certain portions of a preselector unit ofFigs. 1 to 3 inclusive; and

Figs. 5 and 6 show modifications.

Referring to Figs. 1 to 4 inclusive, the device to be indexed is shownas a condenser I0 having stationary plates II and movable platesconstituting a rotor l2. As is customary, the condenser here has rangeof adjustment, al-

later.

Condenser rotor I2 is biased to one end posi- 1 tion by a coil spring l3having one end it rigid on the condenser frame and the inner end l5rigid on rotor shaft it. As shown in Fig. 3, spring i3 tends to maintainthe rotor in the out position so any bias movement is clockwise as seenthere.

Adapted to move the condenser rotor l2 against 'spring i3 is a solenoidI! having an armature l3 operating on cord 20 wound'around sheave 2|dent, solenoid l8 tends to turn condenser rotor anti-clockwise as seenin\Fig. 3. It is under- I stood that other means for providing apermanent bias and a power-drive against the bias may be .provided.

-The remainder of the mechanism is the controlling part thereof and. mayhave any number of units, each unit. controlling one index position.These units are identical to each other in construction. Fig. 1 showstwo such units. More may be provided.

The preselector proper consists of a base 30 of metal or any othermaterial. Base 30 may have its sides 3| and 32 turned up. End plates 33may be providedto complete a frame. End plates 33 rotatably support ashaft 35, which may either be a prolongation of rotor shaft l6 or berigidly coupled thereto. In any event, shafts l6 and 35 operate as acoupled unit. Shaft 35 may be restrained from longitudinal movement inany suitable manner, such as by sleeves 36 and 31 on opposite sides ofend plate 33.

Each preselector-iimit has a washer 40, non rotatable with respect toshaft 35. As shown here, washer 40 has an aperture 4| to accommodateshaft 35 and a tongue 42 is provided to engage a longitudinal slot 43 inshaft 35, thus rotatively locking the washer on the shaft. Washer 40 isround except for a projection 45 extending outwardly and forming anengaging means. Sleeves 46 and 41 may cover shaft 35 on opposite sidesof washer 40. It is understood of course that only one sleeve isnecessary between adjacent units so that sleeve 41 for one unitcorresponds to sleeve 46 for the next unit. Thus the shaft and washers40 travel over a predetermined range angle.

Freely rotatable about shaft 35 (and also about the sleeve) are twomembers. One member is a washer 50 having an aperture with an arcuaterecess 52 bordering on aperture 5| and also having a finger 53 bent overout of the plane of the washer proper. As is evident, washers 40 and 50are so proportioned relative to each other that upon relative rotationtherebetween, finger 53 will travel around the circular edge of washer40 and functions as a stop for pre-engaging projection 45. The othermember 54 is a species of pinion and consists of a cylinder 55 having aseries of apertures 56 regularly spaced around a portion thereof and anengaging finger 51 adapt ed to extend into arcuate recess 52. Thus thesetwo members are freely rotatable with respect to shaft 35 (or thecovering sleeve).

Meshing with pinion 54 is a rack 60 carried by a metal plate 6| whoseapertured ends 62 and 63 are bent down and threaded by a push rod 65.End 62 of plate 6| may slide in a suitable slot in base 30. Push rod 65has one part 66threaded and cooperates with one end 62 of the rackmember to determine the longitudinal position of the rack member on pushrod 65. Thus turning rod 65 will cause the rack member to move one wayor the other along the rod and determine the preselected position.

Push rod 65 is slidably mounted in upturned sides 3| and 32 and extendsbeyond these sides. A push button 61 is at the front end of rod 65 and aspring 68 between side 3| and button 61 biases the rod so that thebutton is normally in a forward or off position. The rear end of the rodhas an enlarged cylindrical head 69 with a tapered conical surface I0.

A latch plate I2 is pivoted by fingers I3 in apertures I4 of 'the endplates so that the plate is below the ends of rods. 65 at the rear ofthe mechanism. A spring I5 tends to pull up the latch plate. The latchplate width is such that in the depressed or on position of a pushrod65, the head will engage the latch plate and retain the rod in its onposition. At the inner edge of the latch plate, a curved cam portion 'IInormally is near or rests against tapered surface I0 of head 69 in theoff position of a rod.- Thus when a rod, such as 65' is normally off orout and is pushed in, tapered surface I0 acts as a cam to push latchplate I2 down from the position shown in Fig. 2. The downward movementThe operation of the device is as follows. Disregarding the solenoid andpreselector action first, it is clear that when any push button ispressed to an on position, the latch plate will be moved to a clearingor down position and permit a previously operated push rod to returnfrom an on to an of! position.

While the latch plate is down, the solenoid circuit is closed and,assuming an electric curthe solenoid circuit is opened, as in Fig. 2,coil spring I3 will turn shaft 35 back toward its first position untilstopped by finger 45 engaging finger 53 as a stop.

In theevent that the power drive is not desired, the mechanism can stillbe operated. In such case, the push rod 65 will have to be moved notonly against its own spring 68 but also against bias spring I3. However,when the power drive is used the rod 65 can be-pushed in with littleeffort since it merely turns finger 53 loosely on its sleeve.

It will be noted that washer cannot turn freely a full 360 with respectto washer 40 before the two fingers engage. This is equivalent to lessthan 180 of range for preselection. In order to give a full 180 range ofadjustment, the arcuate slot 52' engaged by finger 51 is provided. Thisslot subtends a greater angle thanfinger 51 so that in effect the angleof free movement of finger 51 in slot 52 is twice the angle added to therange of adjustment due to fingers 45 and 43.

Thus as an example, if finger 45 subtends an angle of 10 then theeifective range of operation of washers 40 and 50 is 360-10 divided by2, or 175. Now if finger 51 can. move 20 in slot 52 before striking theends, then 10 can of the latch plate is sufficient to permit head 69 beadded on to the range. Thus the entire preselector can pick out anyindex point over an angle of rotation of shaft 35 amounting to Obviouslyby enlarging slot 52 or duplicating washer 50 the angle can be increasedto any desired figure. This is more fully disclosed in Patent No.2,161,183.

It might be noted that, if two or more buttons are operatedsimultaneously, that setting will be chosen which is nearest to theother end position; i. e., furthest away from the coil spring biasedposition, The remaining rods and settings will be idle.

Referring now to Fig. 5, the invention is shown applied to a linearlymovable indexed member. In this figure, transformers I00 and IN eachhave iron dust cores I02 and I03 movable between two end positions alonga straight line. These units are shown as movable in line, but it isobvious that they may be in tandem relation. Any means may be providedfor tracking, if radio receivertuning is involved. As shown here, thecores I02 and I03 are carried by a nonmagnetic rod I05 which, for allpractical purposes, may be considered as the indexed member movable overa linear range between two end positions.

Rod I05 is biased to one end' position by cell gear segment position.

spring H0. The power means for overcoming the spring bias consists of anarmature III on rod I05 cooperating with solenoid H2. Rod I05 alsocarries a'bar I I5 which may extend across the various units to functionas engaging means. The rod travels between fixed stops I05 and I'Ito,determine the range of travel.

Each control unit here shown is of the push rod type, generally similarto the corresponding parts of Figure 1. Each unit includes a push rod 65carrying in adjustable relation therewith a metal plate 6| supporting astop H6, all stops II being adapted to cooperate with bar 5.

When the latch plate-12 is depressed, the solenoid circuit is closed.This results in rod I being 'moved against stop I06. Then when the latchplate is up, the solenoid circuit is broken. The normal spring bias onrod I05 pulls bar H5 forward to the position This, of course, may beadjusted by turning push rod 55, as in Figs. 1 to 4 inclusive. I

In Fig. 6, a. push lever I65 rigidly-joined to a I20 and the lattermeshing with a rack ISO is utilized for moving rod 05' back and forth.In this way, a non-linearly movable push lever I 85 may be used forindexing purposes, The rod 65' may, of course, carry either the rack andpinion means of Figs..1 to 4 inclusive or the finger and stop of Fig. 5as the additional means. Fig. 6 is merely to show that-linearly movablepush rods need not necessarily be used.

What is claimed is:

1. A preselector for use with a device operable over a range between twoend positions, said preselector comprising an indexed member movableover the range to be covered, means for biasing said member havingengaging elements movable therewith over said range, a plurality ofpreselector units, there being one engaging element for each preselectorunit, each preselector unit including a manually operable part movablebetween a released and an actuated position respectively, erable part toits released position, interlocking means for maintaining a manuallyoperable part in its actuated position after reaching the same andreleasing manually operable parts previously set in the actuatedposition, stop means operated by a manually operable part in itsactuated position, said stop means cooperating with an engaging elementon said indexed means, said biasing means for said indexed member urgingsaid engaging element against its cooperating stop means, and meansoperative only when a manually operable member is between a released andan actuated position for moving said indexed member against its biasingmeans to its other end position.

2. The structure of claim 1 wherein said indexed member includes a shaftrotatable over a predetermined angle. y

3. The structure of claim 1 wherein an adjustable connection is providedbetween said stop means and said manually operable part so that therelative position of said stop means controlled spectively,

determined by stop 6.

said shaft to one endposition, engaging elements carried by said shaftand rotatable therewith over said range, and a plurality of preselectorunits, there being one engaging element for each preselector unit. eachpreselector unit including a manually operable member movable between areleased and an actuated position, remeans for biasing each manuallyoperable member to its released position, interlocking means formaintaining a manuallyoperable member in its actuated position afterreaching the same and for releasing manually operable members previouslyset in actuated positions, a stop actuated by a manually operable memberand movableto a predetermined position when said manually operablemember has reached its actuated position, said stop cooperating with anengaging element .on said shaft to determine an index position, saidindexed shaft biasing means urging said engaging element against saidstop, and electromagnetic means controlled by said interlocking meansoperative only when a manumember to one end position, said indexed allyoperable member is between a released and an actuated position formoving said indexed shaft against its bias to its other end position.

5. A preselector for use with a device operable over a range between twoend positions, said preselector comprising an indexed shaft rotatableover the range to be covered, means for biasing said shaft to one endposition,'-engaging elements fixedly carried by said shaft and movabletherewith over said range, and a plurality of preselector units, therebeing, one engaging element for each preselector unit, each preselectorunit including a manually operable member movable between two endpositions, these being a released and an actuated position respectively,means for biasing each manually operable member to its means for biasingeach manually opreleased position, interlocking means for maintaining amanually operable member in its actuated position after reaching thesame and for releasing manually operable members previously setin'actuated positions, a rotatable stop loosely carried by such shaftand having a projection cooperating with an engaging element fixedlymounted on said shaft, said indexed vshaft bias by said manuallyoperable part may be adjusted whereby in the actuated position of saidmanually operable part said stop has a predetermined ad-- justedposition to determine an adjustedindex 4. A preselector for use with adevice operable over a range between two end positions, said preselectorcomprising an indexed shaft rotatable over the range to be covered,means for biasing means urging said engaging element against said stop,means controlled by said manually operable member for moving saidrotatable stop to a predetermined position when said manually operablemember has reached its actuated position, and means controlled by saidinterlocking means operative only when a manually operable member isbetween a released and an actuated position for moving said indexedshaft against its bias to its other end position.

6. A preselector for use with a device operable over a range between twoend positions, said preselector comprising an indexed shaft rotatableover the range to be covered,' means for biasing said shaft to one endposition, said shaft having a plurality of engaging elements movabletherewith over said range, and a plurality of preselector units, therebeing one engaging element for each preselector unit, each preselectorunit including a manually operable member movable between two endpositions, these being a released and an actuated position respectively,means for biasing each manually operable'member to its releasedposition, interlocking meansfor maintaining a manually operable. memberin its actuated position after reaching the same and for releasingmanually operable members previously set in actuated positions, a stopmember rotatable about said shaft for each engaging element, saidindexed shaft bias means urging said last-mentloned engaging elementagainst its stop member, means coupling each manually operable member toits stop member to move the latter to a predetermined position when saidmanually operable member has reached its actuated position, andmeans-operative only when a manually operable member is intermediate itsreleased and actuated positions for moving said indexed shaf against itsbias to its other end position.

'7. A preselector comprising a shaft rotatable over a range between twolimiting positions, a plurality of fingers coupledto said shaft, a pushrod for ,each finger, said rod being longitudinally movable and normallybiased to an off-position and manually movable to an on-position, a rackcarried by said rod and movable therewith, means for adjusting therelative positions of a rack and its rod, and means engaged by said rackincluding a stop cooperating with said last-mentioned finger fordetermining a stopping position for said last-mentioned shaft finger.

8. A preselector comprising a shaft rotatable over a range betweentwolimiting positions, a plurality of fingers coupled to said shaft, a pushrod and a stop controlled thereby for each finger, said rod beinglongitudinally movable between two end positions and being normallybiased to an off-position and manually movable to an on-position, a rackcarried by each rod and adjustable with respect thereto, meanscooperating with said rod to set said stop for the corresponding fingerin a predetermined position, said 7 means being set in saidpredetermined position when the corresponding rod is in its on-position,and means for moving said shaft to a predetermined index positiondetermined by the engagement of said finger and said stop.

9. A preselector comprising a shaft rotatable over a range between .twolimiting positions, a plurality of fingers coupled to said shaft, apushrod for each finger normally biased to an offposition and manuallymovable to an on-position,

a rack carried by each rod and adjustable with respect thereto, meansoperated by said rack upon rod movement to an on-position including aprojection movable within the field of.movement of the correspondingfinger to provide a stop in a predetermined position for saidcorresponding shaft finger, means imposing a constant bias on said shafttending to move said finger against said stop and means operative onlyduring movement of a rod for overcoming said bias and moving said shaftso that said finger is moved away from said stop.

10. A preselector comprising a shaft rotatable over a range between twolimiting positions, a plurality of fingers coupled to said shaft, a rodfor each finger, said rod being normally biased to an off-position andbeing manually movable to an on-position, a rack adjustably carried byeach rod, means including a stop actuated by said racli upon rodmovement, interlocking means for maintaining a rod lockedin anon-position and for releasing previously locked rods, means imposing aconstant bias on said shaft toward one limiting position, and meanscontrolled by said interlocking means and operative only during a rodmovement for overcoming said bias and biasing said shaft toward itsother limiting position.

11. A preselector comprising a shaft rotatable over a range between twolimiting positions, means for biasing said shaft toward one limitingposition, a plurality of fingers coupled to said movable to anon-position,

, shaft, a push-rod for each finger normally biased to a predeterminedposition, power means for overcoming said shaft bias and moving saidshaft toward its other limiting position, and means for controlling saidpower means and rendering said power means operative only during manualoperation of a rod.

12. A preselector for use with a device operable over a range betweentwo limiting .positions, said preselector comprising an index shaftrotatable over a certain range, means for biasing said shaft to onelimiting position, a plurality of fingers coupled to said shaft, aplurality of control units, there beingone control unit for each fingerfor determining an index position, each control unit comprising a pushrod normally biased to an off-position and being manually movable to anon-position, adjustable stop means actuated by a push rod and set to apredetermined index position upon operation of said push rod, anelectric switch actuated by each push rod during manual operationthereof, and means controlled by said electric switch for overcoming oneunit for each finger, each unit consisting of.

a push rod longitudinally movable and being normally biased to anoff-position and being manually movable to an on-position, a rackcoupled to said push-rod, a pinion freely ro table about said shaft andnormally engaging said rack, a

stop actuated by said pinion and moved to a predetermined position uponrod ctuation and means for retaining a stop, after 0d actuation,

in predetermined position to mai tain an index position.

14. A preselector comprising a,shaft rotatable over a range between twolimiting positions, means for biasing said shaft to one limitingposition, a plurality of fingers ca ied by said shaft and rotatabletherewith, a control unit for each 'finger, each control unit co risinga push-rod normally biased to an off-p sition and manually rack movablewith said push rod, a pinion on said shaft actuated by said rack, a stopactuated by said pinion, and interlocking means for maintaining a rod inan on-position after actuation and for releasing previously locked rods.

15. A preselector comprising a shaft rotatable over a range between twolimiting positions, means for biasing said shaft toward one limitingposition, a plurality of fingers carried by said shaft and rotatabletherewith, a control unit for each finger, said control unit including apush rod normally biased to an off-position and manually movable to anon-position, a rack actuated by said push rod, a pinion engaged by saidrack, a stop actuated by said pinion and moved to a predeterminedposition when said rod is in its onposition, interlocking means formaintaining the rod in its on-position and for releasing previously setrods, and electromagnetic means controlled by said interlocking meansfor overcoming said shaft bias means and for moving said shaft towardthe other limiting position upon manual actuation of a rod.

16. A preselector comprising an index member movable over asubstantially straight line between two limiting positions, means forbiasing said member to one limiting position, a bar movable therewith, aplurality of push rods cooperating with said bar, each of said rodsbeing biased to an off-position and manually movable to an JOHN H.WILLIAMS.

